The 3 Macronutrients And Their Functions

Believe it or not, our diets can be broken down into three main macronutrients:¬† fats, proteins, and carbohydrates.¬† What are macronutrients?¬† Simply, they are fats, proteins, and carbohydrates: the materials whose functions are to provide us with the energy and sustenance we need for survival¬†. The term “macro” means large; hence, they¬†quickly and effectively deliver the nutrients we need in large amounts.

Understanding Macronutrients

Macronutrients are actually chemical compounds, or complex forms of chemical elements that we cannot live without.¬† We must consume these chemical compounds in very large amounts in order to stay alive.¬† From a dieting perspecti,ve it can be helpful to look at things that way. Carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorous enable us to live; we must get them from macronutrients (“fuel”).¬† Macronutrients also provide us with the essential macrominerals:

  • calcium
  • salt
  • magnesium
  • potassium

Why is this important? The macronutrients provide the substances we need for growth, metabolism, and body function.  Breaking the macronutrients down into calories per gram helps simplify things.  This may be a review for some, but it is always good to remember the following:

  • Carbohydrates contain 4 calories per gram
  • Fats contain 9 calories per gram
  • Proteins contain 4 calories per gram

This is obviously important to consider when watching calories.¬† At 9 calories per gram, excessive consumption of fats is going to provide way too¬†much energy¬†(calories).¬† We still need fats however, so what’s key is learning to consume the “good” fats in small amounts.¬† For all three macronutrients, we need to understand¬†proper consumption¬†so they don’t slow us down, causing weight gain and fatigue.¬†


Most of our diets should come from them (at least 45-65 percent of our daily intake), because they provide us with the most essential substance for our survival, glucose.  Glucose is actually the only substance our brains use for energy. Aditionally, our central nervous systems, kidneys, and hearts need glucose for basic maintenance.  The majority of essential vitamins and macrominerals we need also come from carbs. Lastly, carbohydrates contain fiber, which helps our intestinal tracts to expel waste properly, in addition to helping us lower cholesterol. 

Stick to fruits, veggies, beans, seeds, nuts, and whole grains for proper carb consumption.  Stay away from starchy foods like white bread, pasta, and potatoes.  Still thinknig about that low-carb diet?  Re-read the above paragraph and think twice about what your body will be missing. 


We need about 10-35 percent of our diets to come from proteins.  They are crucial for tissue repair and growth of children, teens, and pregnant women.  Protein also provides:

  • Essential hormones
  • Amino acids
  • Enzymes
  • Immune functions

Protein is a back-up source of energy, and it also helps us maintain lean muscle mass. Your best protein bets are lean meats, fish, poultry, lean cheeses and milks, soy, legumes, and some seeds.


They sometimes get a bad wrap, but we still need them — they are essential.¬† About 20 percent of our diets should contain fats, it’s just that we need to make sure we eat the proper ones.¬† Fats benefit our health as they:

  • cushion our organs
  • maintain our cell membranes
  • help promote natural growth and development
  • help us absorb some of¬†the most essential vitamins: A, D, E, and K

Replacing certain meats, heavy creams, lard, butters, and certain milk products with olive oils, avocados, nuts, and canola oils is recommended, and it cuts down on the risk of heart disease.

Choosing the Right Macronutrients

For those of you who are wondering, then, why there are so many low-carbohydrate, high protein diets out there, the answer is that they are fads; they are not designed for long-term weight management, and most health professionals will not  recommend them for losing weight and keeping it off. 

It’s up to us to manage our macronutrients and do research — and make an effort.¬† Clearly we are consuming certain foods that provide way too many calories from one kind of macronutrient (i.e., fat and processed carbohydrates) and not enough of the others.¬† Even a bag of baked chips might only have about 120 calories and little fat,¬†but eating it will not feel satisfying and most likely you will¬†crave more (since chips are highly¬†processed and contain too much sodium).¬†¬†Consider an¬†apple with about 5 almonds instead.¬†It is packed with vitamins and good fats.


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